Free platen typewriter

ABSTRACT

The typewriter includes a cylindrical platen having free ends and held in position by a plurality of rollers disposed at circumferential positions about the platen, with the position of each roller being, with respect to the circumference of the platen, less than 180* from the next roller, and one of the rollers being shiftable away from the platen and retainable in its shifted position, to provide a space between the shifted roller and an adjacent roller greater than the diameter of the platen. The typewriter also includes a paper guide having a planar surface wider than the platen, for guiding a sheet of paper or the like downwardly to the underside of the platen, and an approximately semicircular curl disposed outwardly from each end of the platen.

[ 1 Oct. 23, 1973 FREE PLATEN TYPEWRITER [76] Inventor: Cecil S. Effinger, 828 Pearl St.,

Boulder, Colo. 80302 [22] Filed: Nov. 22, 1968 [21] Appl. No.: 784,518

Related U.S. Application Data [63] Continuation-impart of Ser. No. 594,025, Nov. 14,

1966, abandoned.

[52] U.S. Cl...... 197/127 R, 197/138 R, 197/145 R, 197/186 R, 197/143 [51] Int. Cl B4lj 13/00 [58] Field of Search 197/8, 114, 127, 197/133,138,138.5,143,l44,l45,146, 147, 1, 186

[56] References Cited UNITED STATES PATENTS 2,421,119 5/1947 Grief 197/138 A UX 2,131,152 9/1938 Stickney 197/133 2,434,866 l/1948 Rubin 197/143 X 2,672,228 3/1954 Effinger 197/8 2,717,070 9/1955 Letterman 197/114 2,848,092 8/1958 Ostholm et a1. 197/138 2,904,156 9/1959 Effinger 197/8 3,064,790 11/1962 Emig 197/127 3,374,732 3/1968 Mallory et al. 197/186 X 779,408 l/l905 Bruce 197/143 1,012,113 12/1911 Tanner et al. 197/138 1,186,268 6/1916 Barnaby 197/145 X 1,280,678 10/1918 Clamecy.. 197/127 1,293,252 2/1919 Tucker 197/114 1,351,355 8/1920 Tucker 197/114 X 1,411,707 4/1922 Canning...... 197/138 1,524,366 l/1925 Myers et a1. 197/143 1,834,613 12/1931 Going 197/114 1,916,371 7/1933 Helmond 197/138 2,047,359 7/1936 Dayment et al. 197/127 Primary Examiner-Ernest T. Wright, Jr. Att0rneyVan Valkenburgh and Lowe [57] ABSTRACT The typewriter includes a cylindrical platen having free ends and held in position by a plurality of rollers disposed at circumferential positions about the platen, with the position of each roller being, with respect to the circumference of the platen, less than 180 from the next roller, and one of the rollers being shiftable away from the platen and retainable in its shifted position, to provide a space between the shifted roller and an adjacent roller greater than the diameter of the platen. The typewriter also includes a paper guide having a planar surface wider than the platen, for guiding a sheet of paper or the like downwardly to the underside of the platen, and an approximately semicircular curl disposed outwardly from each end of the platen.

2 Claims, 22 Drawing Figures PAIENTEMmza 12m 3 767.023 SHEET 1 0F 6 I INVENTOR.

: Cecil s. Effinger V ATTORNEYS PAIENIEflnms ma 3.767023 sum 2 or e INVENTOR.

Cecil S. Effinger BY I/MVWLAWK ATTORNEYS PAIENIEUIICIZS 1915 3. 767,023 sum 3 OF 6 P/ Fig. 6

INVENTOR.

Cecil S. Effinger ATTORNEYS PATENTED UB1 2 3 I913 SHEEP "0F 6 INVENTOR. Cecil S. Effinger BY 1 W fM ATTORNEYS Pmmmums ma 3.767.023

SHEET 5 0F 6 IN VEN TOR.

Cecil S. E ffinger BY l/ VWY'AM ATTORNEYS PATENIEnucI 23 ms 3 767.023

sum s or 6 IN VEN T OR.

'15! 966i! 8. E ffinger FIG. 2/ 7% m y ew AT TORNE YS FREE PLATEN TYPEWRITER This application is a continuation-in-part of my copending application Ser. No. 594,025 filed Nov. 14, 1966 for Free Platen Typewriter, now abandoned.

This invention relates to free platen typewriters, and more particularly to such a typewriter which is adapted to handle large sheets of paper or the like, on which various types of indicia are to be placed, including but not limited to drawings and diagrams, such as engineering drawings, industrial, electrical or electronic circuit diagrams, heat flow diagrams, highway diagrams and the like.

The typewriter of the present invention may be provided with a keyboard and type bars similar to those of my U. S. Pat. No. 3,388,781 of June 18, 1968. Also, certain of the features of my prior U. S. Pat. Nos. 2,672,228 ofMar. 16,1954, and 2,904,156 ofSept. 15, 1959, may be utilized. Thus, the typewriter of the present invention includes certain of the additional parts and modifications of the conventional typewriter utilized in producing the typewriter of each of the aforesaid patents, but also further additional parts and modifications of a conventional typewriter.

Among the objects of the present invention are to provide a novel typewriter adapted to handle a large sheet of paper or the like for imprinting indicia thereon, including not only parts of drawings or diagrams, but also legends, instructional or informational material or the like, of either a numerical or alphabetical character; to provide such a typewriter which may be produced as such, or which may be produced by converting a conventional typewriter, as through the addition of parts or modification of certain parts of such a conventional typewriter; to provide such a typewriter in which the width of the sheet on which the indicia are to be placed may be greater than the carriage width; to provide such a typewriter in which the lateral position of the sheet may be readily shifted, with or without removal of the sheet from the typewriter; to provide such a typewriter in which the sheet is adequately supported during movement in the typewriter; to provide such a typewriter which may be produced economically; and to provide such a typewriter which will be efficient and effective in operation.

Additional objects and the novel features of this invention will become apparent from the following description, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a front perspective view of a free platen typewriter constructed in accordance with this invention;

FIG. 2 is an end perspective view of the typewriter of FIG. 1, but with a free floating platen and a cover for certain upper front parts of the carriage removed, each to show parts otherwise hidden from view;

FIG. 3 is a condensed fragmentary left end elevation, on an enlarged scale, of the carriage of the typewriter of FIG. 1;

FIG. 4 is a fragmentary right end elevation, on an enlarged scale, of the carriage of the typewriter of FIG. I;

FIG. 5 is a fragmentary end elevation corresponding to a portion of FIG. 4, but showing certain parts in an adjusted position, as for insertion of a new sheet or lateral movement of the sheet;

FIG. 6 is a front elevation of the free floating platen of the typewriter of FIG. 1;

FIG. 7 is a fragmentary end elevation corresponding to a portion of FIG. 3, but showing an alternative construction of a carriage end plate;

FIG. 8 is a top plan view, on an enlarged scale, of the central portion of the carriage of the typewriter of FIG. 1, showing particularly an assembly of lower rollers which support the free floating platen and which also engage the sheet which is inserted in the typewriter;

FIG. 9 is a transverse vertical section, on a further enlarged scale, taken along line 9-9 of FIG. 8;

FIG. 10 is a condensed top plan view of a carriage escapement bar and a vernier adjustment associated therewith;

FIG. 11 is a fragmentary, condensed front perspective view of the right end of the typewriter, corresponding to a portion of FIG. 1, showing an extension of a paper guide plate;

FIG. 12 is a fragmentary rear elevation of the left end of the paper guide plate, provided with an extension similar to that of FIG. 11;

FIG. 13 is a fragmentary front elevation of a pair of toothed rollers mounted on a rod for rotating the same, utilized when the sheet is provided with sets of indexing holes;

FIG. 14 is a transverse vertical section, on a slightly enlarged scale, taken at the position of one of the rollers of FIG. 13 and showing also the modified construction of the free floating platen associated therewith;

FIG. 15 is a front perspective view, on a reduced scale, of a free platen typewriter constructed in accordance with this invention and comprising an additional embodiment thereof, with a large sheet of paper in typing position;

FIG. 16 is a left end elevation, on an enlarged scale, of the carriage of the typewriter of FIG. 15 but without the sheet of paper;

FIG. 17 is a fragmentary vertical section, on a further enlarged scale, taken along line l7l7 of FIG. 15 and showing particularly a shift lever for an upper roller shaft, and parts associated therewith;

FIG. 18 is a fragmentary vertical section similar to FIG. 17 but showing the rollers mounted on the upper roller shaft moved away from the platen to permit the platen to be lifted bodily upwardly from the carriage;

FIG. 19 is a fragmentary front elevation of a portion of FIG. 17, showing particularly a gear case, the shift lever and the upper roller shaft and parts associated therewith;

FIG. 20 is a fragmentary vertical section, taken along line 20-20 of FIG. 17 and showing particularly the connection of the shift lever to a latch tube and the connection of a shift lever support shaft to one side of the gear casing;

FIG. 21 is an end view, on an enlarged scale, of the support shaft of FIG. 20; and

FIG. 22 is an end view, on an enlarged scale, of an eccentric bushing with which the shift lever of FIGS. 17 and 18 is associated.

In conventional typewriters, the width of the sheet of paper or the like, on which numerical or alphabetical characters or other indicia are to be placed, is limited by the width of the platen and by the width of carriage v movement. Whether the paper itself is mounted on a movable carriage or the type elements are mounted on a movable carriage does not affect this limitation on the width of the paper which may be conveniently used. Typewriters have, of course, been made with special carriages of considerable width, but such widths are limited by the overhanging weight which can be adequately supported with the carriage at the extreme end positions of its movement, as well as by the difficulty of adequately supporting, in aligned position, a platen having a considerable distance between its ends. In fact, platens for wide carriage typewriters are frequently tapered from the center outward, to accommodate bowing of the platen. Special typewriters have also been made with end openings through which the paper is inserted, in rolled condition, into a circular space and then feeding past a fixed platen to the printing area and permitting lateral shifting of the paper. However, the positioning of the paper is awkward and time consuming, usually with no visilbility of the printing point, and both placement and removal at an intermediate position of the paper are limited to endwise movement. With typewriters heretofore available, it is impossible or awkward and difficult accurately to place indicia on a sheet having a width of, say, 3 to 6 feet.

A typewriter of this invention, as in FIGS. 1 and 2, is provided with a free floating platen P which is supported on an open end carriage C and maintained in contact with the sheet of paper or the like by a lower roller assembly A and an upper roller 20, with the lower roller assembly A being a cradle type structure, which will be described in detail later, and the upper roller being mounted on a rod 21 which is turned by a knob 22, conveniently at the left end. Rod 21 and roller 20 with it, is adjusted toward and away from the platen P by a lever 23, conveniently at the right end of the carriage C. It will be understood that, as in FIGS. 3 and 4, the platen P may be considered as engaging lower rollers 24 and 25 of roller assembly A at the bottom and also, at the top, engaged by the upper roller 20, although in use, the sheet of paper or the like will be between the platen P and the respective rollers 20, 24 and 25. Although the upper roller 20 presses the platen P toward the lower rollers 24 and 25, the platen P is otherwise free floating, i.e. the platen P can be shifted laterally or the platen P can be removed from the carriage C in an upward or endwise direction, when the pressure against the platen P is released, as by moving the upper roller 20 away from the platen P by shifting lever 23, as in FIG. 5. Thus, the sheet of paper or the like can then be shifted laterally, without removal from the carriage C. For such shifting, it is necessary merely to pull the paper laterally along the carriage C in the direction in which the paper is to be shifted and, as the free floating platen P tends to move with the paper, merely reposition or restrain movement of the platen with the other hand. Nor does the paper need to be rolled up to fit a restricted circular space in the typewriter, for shifting to a different longitudinal position which a shift to a different lateral position is made.

It will be noted that the paper is rolled around the platen P, not by turning the platen directly, as in the conventional typewriter, but by turning the upper roller 20. For this reason, the diameter of the upper roller 20 corresponds to that of the platen P, as in FIGS. 3 and 4, although other ratios of the diameter of the upper roller 20 to the platen P may be utilized. As will be evident, the length of the platen P and carriage C need be no more than that of a standard, conventional typewriter whose carriage corresponds generally to the frame F of the typewriter, although it is preferred to use a slightly wider carriage, in order to provide greater width of the area in which indicia may be applied without shifting the paper laterally. The platen P, as in FIGS. 4 and 6, may comprise a tube 26, as of aluminum, having a knurled portion 27 at each end, for easier gripping for removal or shifting, and also a resilient covering layer 28, spaced from each end and formed of a suitable material, such as fairly hard rubber, Platen P may be 36 inches long and 1% inches in maximum diameter, although any other suitable dimensions may be utilized. The resilient covering 28 forms a conventional backing for the paper at the position at which the type characters strike the paper. Relatively thin tubing can be used, since platen P is not subjected to the strain of being supported by bearings at the ends, but rather is supported by the plurality of lower rollers 24,25 which provide elongated bearing areas, with the inner lower rollers 24,25 close to the point of applied force by the upper roller 20. This support permits a mucn greater maintenance of accuracy in alignment, without undue deflection of the platen P, than would be otherwise possible, further permitting maximum freedom of rotation in relation to the pressure necessary to turn the sheet.

In further accordance with this. invention, the typewriter is provided with a paper guide G having a generally flat portion 30 which slants upwardly from front to rear, from a point just above and behind the rear lower rollers 25, and a pair of preferably integral curls 31 at each end and flanking the lower roller assembly A, each curl 31 being ayproximately semicircular and having an inside radius slightly greater than the maximum diameter of the platen P, as in FIG. 4. The curved top 32 of the paper guide G may be approximately semicircular but inclined rearwardly so that the sheet will move smoothly thereover, while the rear face 33 curves downwardly and then forwardly underneath, to assist movement of the sheet from or to the surface on which the typewriter is placed. The paper guide G may also have any other configuration which presents a smoothlycurving surface, which guides thepaper upwardly from the rear, downwardly to the platen P, around the platen P, upwardly and rearwardly at the front, then rearwardly over the topof the paper guide G, moving over the portion of the sheet concurrently moving forwardly. As will be evident, in general, the sheet inserted around the platen P will follow the curvature of the paper guide G. The end curls 31, particularly, support any overhang of the sheet at each end of the platen P and will produce a smooth curve in the sheet laterally from the platen P at each end, corresponding to the curve around the platen P. Thus, the paper guide G will support, both for typing and particularly for turning with the platen P, a sheet which is much wider than the width of the paper guide G itself. When extreme widths of the sheet are being used, such as 5 to 6 feet, and with a paper guide G approximately 36 inches in width, an extension'E may be attached to each end of the guide G, as will be described later.

A left end plate L and a right end plate R are attached to the ends of the carriage C, which moves laterally between a pair of spaced guide bars 34 of frame F, as in FIG. 2, it being noted that the carriage C is shown in a central position in FIG. 1 but in FIG. 2 moved to the extreme right, into engagement with a restriction bar similar to movement restriction bar 35 at the left. A pair of screws 36 of FIG. 2 may be utilized in attaching left end plate L to the carriage C, with similar screws 36 attaching right end plate R to the right end of the carriage C, as in FIG. 4. Each end plate L and R, as in FIGS. 2, 3 and 4, is conventional in shape at the bottom but extends rearwardly beneath the paper guide G and the edge thereof corresponds to the inside contour of paper guide G, as shown, with the paper guide G extending laterally outwardly past each end plate L,R and attached to each end plate L,R in a suitable manner, as by welding. At the front, a post 37 of each end plate L,R extends upwardly and forwardly, having a rear edge corresponding to the contour of curl 31, to an enlarged head 38 for supporting the rod 21 and parts associated therewith, such parts at the left, except knob 22, being normally enclosed by a housing 39, as in FIG. 1. As in FIG. 11, a modified right end plate R, similar to a conventional end plate R at the front, may be used. As in FIGS. 2 and 3, the left end of rod 21 is supported for rotation by a bearing 40, which is mounted in head 38 at an appropriate position. A shaft 41, on which both adjusting knob 22 and a gear 42 are mounted, is also mounted for rotation in a sleeve bearing 43, in turn mounted on head 38, with knob 22 outside and gear 42 inside head 38.

Gear 42 meshes with a similar gear 44, mounted on rod 21, so that when the knob 22 is turned in the usual direction to move the sheet upwardly in the typewriter, the same direction of movement will be imparted thereto by turning the knob 22, as well as when the knob 22 is turned to move the sheet downwardly in the typewriter. It will be noted that, since the upper roller 20 is used to turn the paper or sheet and also the platen P, the interposition of gears 42 and 44 between knob 22 and rod 21 permits the knob 22 to be turned in the normal manner, so that anyone accustomed to a knob attached to a platen, for turning the platen in a conventional typewriter, will not be confused by the movement of the sheet being controlled by roller 20, instead of the platen P.

Av detent mechanism is also provided, so that the distance which the carriage C is normally caused to travel horizontally through the escapement mechanism is equal to or a small integer multiple of the distance which the sheet is normally moved vertically. Thus, the number of teeth on gears 42 and 44 is selected so that this desired ratio is obtained. For instance, with a roller 20 having a diameter of l 1% inches, 75 teeth on gear 44 will produce a movement of one-sixteenth inch of the sheet by turning gear 44 an increment of one tooth. The detent mechanism, as in FIGS. 2 and 3, may include a detent gear 45 mounted on rod 21 outside the end plate L and a detent 46 mounted on a longer arm of an angular lever 47 to extend laterally therefrom, so that detent 46 will normally engage the teeth of gear 45. A notch may be cut in curl 31 opposite gear 45, if necessary to accommodate the same. Lever 47 is pivoted on a pin 48, while a spring 49, connected between a shorter arm of lever 47 and head 38, maintains detent 46 normally in engagement with the teeth of gear 45, so that knob 22 may be turned until detent 46 clicks into the next tooth, and the sheet will have been moved a desired increment of distance. Of course, provision is also made to permit the sheet to be freely moved upwardly and downwardly in the typewriter; for this purpose, the flat outer end 50 of the longer arm of lever 47 is offset to provide a curved notch, as shown, normally spaced from a pin 51 mounted on the lower end of a lever 52, in turn pivoted on a pin 53 mounted on head 38. As will be evident, with lever 52 in the posi tion of FIG. 3, detent 46 may act in the usual manner. However, when lever 52 is pushed rearwardly, to the position of FIG. 2, pin 51 will engage the notch and slip onto the flat end of the longer arm of angular lever 47, to hold detent 46 away from gear 45, thereby permitting free movement of the paper when knob 22 is turned.

Head 38 of right end plate R, as in FIG. 4, is conveniently, but not necessarily, similar in shape to head 38 of the left end plate L, but is provided with different holes or slots for supporting different parts, such as a forwardly and upwardly inclined slot 55 which receives a bearing 56 for the reduced right end of rod 21. The rod 21 and bearing 56 are movable in a slot 55 from the lower or clamping position of FIG. 4 to the upper or release position of FIG. 5, as by a fork 57 extending angularly from the lower end of lever 23, which is pivoted on a pin 58. A toggle spring 59, connected between head 38 at a point 592 forwardly and below pin 58 and the lower arm of fork 57, holds lever 23 in either position, since spring 59 holds fork 57 downwardly in the position of FIG. 4, the spring 59 then being below pin 58. In the position of FIG. 5, the spring 59 holds fork 57 in an upper position, since the spring 59 then is above pin 58. In the position of FIG. 4, spring 59 also holds upper roller 20 downwardly and urges it toward platen P, so that the upper roller 20 will frictionally engage the sheet and move the sheet, as well as rotate the platen P, a distance corresponding to the amount which rod 21 is turned by knob 22. As in FIG. 4, it will be noted that the axis of rotation of the front lower roller 24 is preferably approximately below the upper roller 20, while the axis of rotation of the rear lower roller 25 is rearwardly therefrom and rear lower roller 25 is also elevated with respect to front lower roller 24, so that upper roller 20 will push the platen P toward each of the lower rollers 24 and 25. However, when it is desired to remove or replace the platen P from above, the upper roller 20 need be shifted only a slight distance to provide sufficient clearance, as from the position of FIG. 4 to the position of FIG. 5.

That said platen P may be lifted bodily from the carriage C and returned, i.e., removed or replaced from above when roller 20 is shifted to the position of FIG. 5, will be evident from FIGS. 3, 4 and 5. As in FIGS. 3 and 4, the points of engagement of the roller means engaging the platen P from beneath, exemplified by the rollers 24 and 25, are shown as spaced between and apart, while the point of engagement of roller 20 is between and from roller 24 and between and from roller 25, Le. each of the angles is less than Thus, with three such rollers, 20,24,25

with each space between any two adjacent rollers less than 180, the platen P is held against radial movement, as distinguished from rotation, during imprinting of indica on the paper controlled by the platen P. However, when the roller 20 is shifted to the position of FIG. 5, the straight line distance between rollers 20 and 25 is greater than the diameter of the platen P, so that the platen P may then be lifted bodily from the carriage C, as well as replaced. A further advantage of being able to lift the platen P bodily from the carriage C and replace it bodily, without endwise movement, particularly in the case of large sheets of paper, is in endwise adjustment of the paper relative to the platen P, since the roller 20 may be shifted to the position of FIG. 5, the paper held together above the platen P to lift the platen bodily from the carriage C, the platen P moved endwise to a desired position, as by pulling on the platen P, and end edges of the paper brought together for accurate longitudinal alignment and the platen P replaced, such as largely by gravity. The longitudinal position of the platen P on the carriage C may also be adjusted in a similar manner, when no adjustment of the relative position of the plate P to the paper is to be made. Lifting the platen P bodily from the carriage C is preferable to shifting the paper endwise, while the platen P rests on rollers 24 and 25, even though upper roller 20 is shifted to relieve pressure on the platen P, since such pulling of the paper endwise tends to cause rollers 24 and 25 to rub against indicia already on the paper and smudge, blur or erase parts of them. It will be noted that, when the plate P is lifted bodily by the paper and then shifted endwise, the platen P is moving against the inside of the paper and not against any indicia previously placed on the paper.

Since it is desirable to position upper roller 20 so that it will exert a sufficient pressure against the platen P that the sheet of paper or the like will be held securely, but the platen P can still be rotated with sufficient ease, it may be desirable, in some instances, to be able to adjust the position of rod 21. This is conveniently accomplished by making post 37 and head 38 of left end plate L as separate parts, rather than integral as in FIG. 7, in which post 37 terminates at a desired position, such as that shown, and head 38, which is otherwise similar to head 38 of FIG. 3, is provided with a downwardly extending extension 60 having a pair of slots 61, with corresponding slots provided in the upper end of post 37' and adjustment bolts 62 extending through the slots 61.

The lower roller assembly A, as in FIGS. 8 and 9, is mounted on the base of carriage C, which comprises a pair of ways 65 having grooves 66 on the outside engaging roller bearings which in turn engage similar grooves on the inside of each guide bar 34 of FIG. 2 and connected at appropriate intermediate positions by slotted cross bars 67 and at the ends by upstanding end bars 68, to the latter of which the left and right end plates L and R, respectively, are attached. Ways 65 and bars 67 and 68 are conveniently formed integrally, as by casting, with finished surfaces being machined, Each side of cross bar 67 is provided with a central, upstanding boss 67a on which a bracket 69 is mounted, as by cap screws 69a. Each bracket 69 is provided with a depending boss 70, at each side, for receiving a set screw 71, by which the position of the four sets of front lower rollers 24 and rear lower rollers 25 are adjusted. The two lower front rollers 24, at the left, are mounted on a shaft 72 of FIG. 9, with the two front lower rollers 24 at the right being mounted on a similar shaft, while the two rear lower rollers 25, at the left, are mounted on a shaft 73 of FIG. 9, with the two rear lower rollers 25 at the right being mounted on a similar shaft. Each shaft 72 is rotatably and removably received in a slot 74 at the outer end of a supporting bracket 75, the inner end of which is pivoted on a pin 76, in turn mounted on bracket 69, while rollers 24 are maintained longitudinally by spacers 77. As shown, one of the set screws 71 engages a lug 71a depending generally centrally from pivoted bracket 75. As will be evident there are three pivoted supporting brackets 75 for each pair of front lower rollers 24. The rear lower rollers 25 are similarly mounted, with each shaft 73 rotatably and removably received in a slot 78 at the upper end of an upper arm 79 of a V-shaped pivot bracket which is pivoted at the center on pin 76, alongside pivoted bracket 75, and the lower arm 80 of which is provided with a lug 71b, engaged by the opposite set screw 71. Set screws 71 are precisely adjusted for accurate alignment of the platen P and particularly positioning of the platen P, so that the type bars will engage the sheet of paper or the like at a position precisely corresponding to that at which the concave curvature of the type will fit the convex curvature of the platen P. Although such set screws 71 are conventional, they do permit the advantages of a platen P which is solidly supported and not unduly deflected by pressure to be fully realized.

The sheet of paper or the like is also guided around platen P, between rollers 24 and 25, by a paper guide 82, conveniently formed of thin sheet metal and having a curvature as shown in FIG. 9, with one paper guide 82 for each pair of rollers 24 and 25, as in FIG. 8. Each paper guide 82 is provided with an elongated, rectangular notch 83, through each of which a front roller 24 extends, and a rear slot 84, in which each rear roller 25 is located. The paper guides 82 are pivotally mounted by downwardly extending ears 85 which engage shaft 72 for the corresponding front rollers 24 and correspond in curvature to the curls 31 of paper guide G, except for a rearwardly extending flange 86 on each side of rear slots 84, as in FIG. 9. The flat portion of- 30 paper guide G forms a continuation at the rear of the paper guides 82 above rear rollers 25, as in FIG. 9.

When the sheet of paper or the like to which the indicia are being applied is considerably wider than the paper guide G, end extensions E of FIGS. 11 and 12 may be utilized. Such end extensions E are desirably merely slipped onto the paper guide G, from each end, each having a flat surface 88, corresponding to flat surface 30 of paper guide G, a curved top 89, corresponding to a major portion of the curved top 32 of paper guide G, and a lower front curved portion 90, which corresponds to a major portion of curl 31. The end extensions E need not correspond completely to the shape of the paper guide G, since the end extensions E primarily provide a support for the portion of the paper or the like which curves around the lower portion of the platen P, in order to prevent a fold from being formed in the extending sides of the paper. Thus, the curved lower front portions 90, as well as curved top 89, may terminate short of the corresponding parts 31,32 of the paper guide G. The end extensions E may be attached to the paper guide G in any suitable manner, preferably being easily attachable and removable, as by spring clips 91, each of which carries a pin 92 55 mounted on the outer end thereof and is attached in any suitable manner, as by welding, to the underside of the extension B. Each pin 92 is inserted in a hole in a block 93, attached to paper guide G at a corresponding position. As in FIGS. 11 and 12, one spring clip 91 may be placed adjacent the front edge of an end extension E, another spring clip 91 at the bottom, and another spring clip 91 at the rear.

The typewriter of this invention may be a manual typewriter or may be electrically driven, as well as electrically controlled. Since such a typewriter is particularly adapted to make drawings or diagrams, as well as to type legends or other indicia on the paper or the like, and also may be computer controlled, it may be desirable, in the latter instance, to provide registering holes in the paper, so that any splippage of the paper or between the upper roller 20 and the platen P is constantly corrected. For such purpose, registering wheels 94 having extending knobs 95, as in FIG. 13, may be mounted on rod 21, in lieu of central roller 20. As in FIG. 14, knobs 95 are adapted to engage holes 96 in the paper 97, disposed in correspondingly spaced rows, and are accommodated by correspondingly shaped indentations 98 in the covering layer 28 of a platen P, which otherwise may correspond to platen P of FIG. 6. The free floating platen P permits the paper 97 to be inserted in the typewriter or removed threfrom at any po sition of a long length of paper, or shifted laterally for registration with one or more different rows of holes.

As in FIG. 10, the typewriter of this invention may be provided with a vernier adjustment V for the carriage C, in a manner similar to that of my U. S. Pat. No. 2,904,156, thus being installed between end plates L and R. Vernier V includes a knurled knob 100 having screw threads 101 at the inner end, adapted to engage a nut 102 attached, as by spot welding or brazing, to carriage end plate L. The inner end of vernier knob 100 may be attached for rotation, as by a screw 103, to a bracket 104 which is connected to a rack 105 of the escapement mechanism, rack 105 having teeth 106 and normally being attached by a bracket 107 to the carriage end plate R. However, the usual hole by which bracket 107 is attached, as by a nut and bolt, to end plate R, instead engages a pin 108 attached to carriage plate R, so that, upon adjustment of vernier knob 100, the carriage C can be moved and pin 108 on end plate R will merely slide in bracket 107. The length of travel of vernier knob 100 by means of the screw threads 101 is preferably longer than the distance which carriage C is moved by one complete actuation ofa space bar 109, shown in FIGS. 1 and 2.

Referring now to FIG. 1, the typewriter of this invention may be provided with a keyboard K, similar to that of the typewriter of my U. S. Pat. No. 3,388,781, or any other suitable keyboard, and may include, in addition to space bar 109, a ribbon spool 110, from which a ribbon 111 is fed past the printing point through a ribbon guide having bars 112, and the exact printing point is indicated to the user by the printing point indicator 113, constructed as in my U. S. Pat. No. 2,904,156. The typewriter may further be provided with conventional shift keys 114, with which conventional shift locking keys 114a are associated, and a back space key 114b, as well as other keys, tabs or levers, as desired, either conventional or as disclosed in my aforesaid patents.

In the additional embodiment of FIGS. -22, the

' free platen typewriter shown is similar in many respects to the embodiment previously described. thus, the frame F, as in FIG. 15 is provided with a keyboard K, which may be similar to that previously described, as well as additional keys for various operations and functions, as indicated previously. The carriage C may be similar to the carriage C of FIG. 1, while the platen P may be similar in construction to the platen P of FIG. 3. Thus, platen P, as in FIG. 17, may comprise a metal tube 26, such as aluminum, provided with a resilient covering 28, such as fairly hard rubber. The carriage C, as in FIG. 15, is adapted to receive a paper sheet S which is relatively long and may not only be wider than the carriage C but also wider than the paper guide G which overhangs the ends of the carriage C, as before, and is mounted on a left end plate L and a corresponding right end plate. The vertical rear edge 115 of each front post 37" provides additional clearance for bodily upward movement of the platen P. As in FIG. 16, the paper guide G may be provided with a flat surface 30 extending downwardly toward the platen P, a curved top 32 and a rear face 33, as before, as well as end curls 31' which extend forwardly and upwardly about the platen P, as for a slightly lesser distance than the end curls 31 of FIGS. 2 and 3. The carriage C includes guide bars 34, as before, as well as a roller assembly which may be constructed similar to the roller assembly A of FIGS. 8 and 9, thus including a pair of lower rollers 24 and 25 spaced approximately apart, as in FIG. 16, to rotatively support the platen P. Carriage C is also adapted to support a series of upper rollers 20' and 20", which may be three in number and mounted on a rod or roller shaft 21' by which the roller 20 is turned to move the paper around the platen P. Roller 20 is disposed generally centrally of the carriage C and is utilized to turn the platen P and thereby move the paper around the platen P. Rollers 20" are preferably slightly less in diameter than roller 20 and are utilized merely to guide the paper around the platen P, being slidable along the rod 21' for advantageous placement, such as towards the sides of the carriageC, as shown. However, any other suitable number and arrangement of upper rollers 20, 20 may be utilized. As before, the central roller 20' desirably has the same diameter as the platen P to provide a one to one ratio in turning the platon P. The rod 21' may be turned in either direction by a knob 22, somewhat larger than knob 22 of FIG. 1 and operating through a gear train and detent mechanism contained in a gear box or housing 39', with the parts inside the housing 39 being similar to those previously described in connection with FIGS. 2 and 3, although any other suitable conventional arrangement of the gear train and associated parts may be utilized. Also, a motorized drive for the rod 21 may be installed within the gear box 39', particularly when the typewriter is an electric typewriter with a conventional key or keys (not shown) mounted on frame F, to cause the rod 21 to be turned through suitable increments by the electric motor. As before, the lever 52 for disengaging the detent mechanism, such as previously described and normally contained in the gear box 39, extends into the gear box 39'.

For a purpose and to produce results similar to those previously described, the rollers 20 and 20" are adapted to be moved away from the platen P to provide a space between roller 25 and each roller 20' or 20" greater than the diameter of the platen P and sufficient to permit the platen P to be lifted bodily upward from the carriage C. One difference between the embodi ment shown in FIGS. 15-22 and the previous embodiment lies in the fact that both ends of rod 21' are moved away from the platen P through appropriate movement of a latching shift lever 23mounted at opposite sides of the carriage C', as between the positions of FIGS. 17 and 18. Also, rod 21 moves with the gear box 39 and a bracket 116 at the opposite side of the carriage C, while the vertical rear edge of post 37 permits the platen P to be moved or removed in a vertical direction. Gear box 39 is pivoted, as by a pin 117, while a similar pin is provided for bracket 116. The configuration of the upstanding posts 37" at the front of the left end plate L and the corresponding right end plate is appropriate for the pivoting of the gear box 39 on one post 37" and bracket 116 on the other post 37". Also, each post 37", as in FIG. 17, is

provided at its upper end with a forward extension 118, t

on which is mounted an eccentric bushing 119, for a purpose described below.

As indicated previously, either of the latching shift levers 23' are adapted to be moved forwardly, i.e., toward the operator, to shift the rod 21 away from the platen P and, with it, the upper rollers and 20". For this purpose, the shift levers 23 are each attached, as by spot welding, to a connecting tube 120 at a position which is spaced slightly from the gear box 39' for one shift lever 23', as in FIG. 19, and a corresponding distance from the bracket 116 for the other shift lever 23'. The shift lever tube 120 surrounds a support shaft 121, which is connected to the gear box 39 at one end and to the bracket 116 at the opposite end, with rod 21 being mounted for rotation in a conventional manner in the gear box 39' and on the bracket 116. Each shift lever 23 may be stamped from a flat piece of metal to the peripheral contour shown in FIG. 17 and to provide at the top a lateral tab 122, as in FIG. 19, which facilitates movement of either shift lever 23 by finger pressure, and at the bottom a depending tab 123. The notch between the front edge of tab 123 and a short edge 124, which is generally perpendicular to the front edge of tab 123, engages eccentric bushing 119 to act as a stop to control the pressure which roller 20 will exert against the paper extending around the platen P and to hold upper roller 20' in a rigid and unyielding position, as described below. Edge 124 merges with an arcuate corner 125, the purpose of which will be described below. Each shift lever 23, as in FIGS. 17 and 19, is biased by a coil spring 127 which extends between a pin 128 mounted on the shift lever 23 and a pin 129 mounted on a side plate 132 of the gear box 39, with a pin corresponding to pin 129 being mounted on bracket 116.

Each end of the support shaft 121, as in FIG. 21, is provided with a threaded axially extending hole 130 and a pair of flat shoulders 131 which fit into a correspondingly shaped slot in a side plate 132 of gear box 39', as in FIG. 20, for attachment of the support shaft 121 to side plate 132 by a screw 133, the head of which bears against a washer 134. The opposite end of support shaft 121 is attached, as in an identical manner, to bracket 116. The eccentric bushing 119, as in FIG. 22, has a hexagonal head, as shown, and a concentric, laterally extending, annular shoulder 136 having an eccentric hole 137 therethrough. The eccentric bushing 119 may be mounted on extension 118 of a post 37" by a screw 138 which extends into a tapped hole in extension l18, with a washer 139 between the head of screw 138 and shoulder 136, as in FIG. 19. Through loosening of screw 138 and turning eccentric bushing 119 by means of its hex head, then retightening screw 138, the eccentric bushing 119 may be adjusted so that the engagement therewith of edge 124, and thus the relative position of the roller 20' and platen P, may be adjusted to provide a rigid position of roller 20' which will produce the desired pressure against the paper, so that it will readily roll around the platen P, but the paper will be engaged sufficiently tightly by the roller 20'. As in FIG. 19, the lower end of each shift lever 23 engages the annular shoulder 136 of the eccentric bushing 119 between the hex head thereof and washer 139.

A stop pin 140 extends laterally from the side plate 132 of gear box 39, with a similar stop pin being mounted on bracket 116 at an appropriate position such that, when either shift lever 23 is moved forwardly against the pressure of spring 127, the opposite shift lever 23' will also be moved similarly to simultaneously tip the gear box 39' and bracket 116 from the position of FIG. 17 to the position of FIG. 18 and space the rollers 20', 20" from the platen P, so that the platen P may be moved bodily upwardly. In the position of FIG. 18, stop pin 140 engages the upper edge of post extension 118, as shown in dotted lines, to limit further forward movement of gear box 39' at one side and bracket 116 at the opposite side, while the shift lever 23 rests on the annular shoulder 136 of the eccentric bushing 119, at or adjacent to the arcuate corner 125. As will be evident from FIG. 18, when the roller 20' is so shifted, its rear edge will be approximately directly above vertical edge of the post 37", again to permit the platen P to be moved or removed in a vertical direction, which is of substantial advantage in lifting the platen P by the paper and generally handling large sheets of paper. The weight of the upper roller assembly, including the gear box 39 and parts therein, as well as bracket 116, tube and shaft 121, maintain the upper roller assembly in that position. That is, the upper roller assembly will stay in that position until one or the other shift lever 23', or the gear box 39 or tube 120 is flipped rearwardly, to move the roller 20 again into engagement with the paper around the platen P.

Although two different embodiments of this invention have been illustrated and described, itwill be understood that other embodiments may exist and that various changes and variations may be made in the free platen typewriter of this invention, without departing from the spirit and scope thereof.

What is claimed is:

1. In a typewriter provided with a carriage having end plates:

a cylindrical platen having free ends and around which an elongated sheet of paper or the like having a width greater than the length of said platen may be wound, said end plates being formed so as to leave unobstructed the area at each end of said platen;

a pair of rollers mounted on said carriage for supporting said platen for rotation and disposed at positions less than apart with respect to the circumference of said platen;

a third roller disposed centrally with respect to said carriage and limited in longitudinal extent, said third roller being disposed at a position opposed to said pair of rollers and engageable with said platen at a position spaced less than 180 from each of said pair of rollers;

one end plate of said carriage having an inclined slot;

a rotatable rod normally disposed parallel to the axis of said platen, said third roller being secured to said rod and one end of said rod being disposed in said inclined slot;

the opposite end of said rod being rotatably mounted on the opposite end plate of said carriage;

means for turning said rod mounted on said opposite end plate for turning said third roller to impart rotational movement to said platen;

a shift lever having a bifurcated end pivotally mounted on said one end plate, said bifurcated end engaging said one end of said rod;

said shift lever being arranged to shift said one end of said rod to shift said third roller to a position spaced from one of said pair of rollers a distance greater than the diameter of said platen; and

a spring extending between said bifurcated end of said shift lever and said one end plate and arranged to maintain said shift lever and said rod in positions at opposite ends of said inclined slot.

2. In a typewriter provided with a carriage having end plates:

a cylindrical platen having free ends and around which an elongated sheet of paper or the like having a width greater than the length of said platen may be wound;

a pair of rollers mounted on said carriage for supporting said platen for rotation and disposed at positions less than 180 apart with respect to the circumferenee of said platen;

a rotatable rod normally disposed parallel to the axis of said platen and disposed at a position opposed to said pair of rollers at a position spaced less than 180 from each of said pair of rollers;

a third roller secured to said rod and engageable with said platen for imparting rotational movement to said platen;

each said end plate being provided with a front post having a substantially vertical rear edge but leaving unobstructed the area endwise of said platen;

a casing pivotally mounted on said front post of one end plate, one end of said rod being rotatably mounted on said casing;

means supported by said casing for turning said rod to turn said platen and move paper or the like around said platen with said third roller in engagement with said paper;

a bracket pivoted on said front post of the opposite end plate, the opposite end of said rod being rotatably mounted on said bracket;

a latch lever pivotally mounted on each of said casing and bracket, said latch levers being connected for simultaneous movement and each latch lever having a notch providing a transverse edge, said latch levers being movable to shift said third roller to a position spaced from one of said pair of rollers a distance greater than the diameter of said platen; and

means on each said front post for engaging said transverse edge of the corresponding latch lever, said means being adjustable to maintain said third roller in engagement with said platen. 

1. In a typewriter provided with a carriage having end plates: a cylindrical platen having free ends and around which an elongated sheet of paper or the like having a width greater than the length of said platen may be wound, said end plates being formed so as to leave unobstructed the area at each end of said platen; a pair of rollers mounted on said carriage for supporting said platen for rotation and disposed at positions less than 180* apart with respect to the circumference of said platen; a third roller disposed centrally with respect to said carriage and limited in longitudinal extent, said third roller being disposed at a position opposed to said pair of rollers and engageable with said platen at a position spaced less than 180* from each of said pair of rollers; one end plate of said carriage having an inclined slot; a rotatable rod normally disposed parallel to the axis of said platen, said third roller being secured to said rod and one end of said rod being disposed in said inclined slot; the opposite end of said rod being rotatably mounted on the opposite end plate of said carriage; means for turning said rod mounted on said opposite end plate for turning said third roller to impart rotational movement to said platen; a shift lever having a bifurcated end pivotally mounted on said one end plate, said bifurcated end engaging said one end of said rod; said shift lever being arranged to shift said one end of said rod to shift said third roller to a position spaced from one of said pair of rollers a distance greater than the diameter of said platen; and a spring extending between said bifurcated end of said shift lever and said one end plate and arranged to maintain said shift lever and said rod in positions at opposite ends of said inclined slot.
 2. In a typewriter provided with a carriage having end plates: a cylindrical platen having free ends and around which an elongated sheet of paper or the like having a width greater than the length of said platen may be wound; a pair of rollers mounted on said carriage for supporting said platen for rotation and disposed at positions less than 180* apart with respect to the circumference of said platen; a rotatable rod normally disposed parallel to the axis of said platen and disposed at a position opposed to said pair of rollers at a position spaced less than 180* from each of said pair of rollers; a third roller secured to said rod and engageable with said platen for imparting rotational movement to said platen; each said end plate being provided with a front post having a substantially vertical rear edge but leaving unobstructed the area endwise of said platen; a casing pivotally mounted on said front post of one end plate, one end of said rod being rotatably mounted on said casing; means supported by said casing for turning said rod to turn said platen and move paper or the like around said platen with said third roller in engagement with said paper; a bracket pivoted on said front post of the opposite end plate, the opposite end of said rod being rotatably mounted on said bracket; a latch lever pivotally mounted on each of said casing and bracket, said latch levers being connected for simultaneous movement and each latch lever having a notch providing a transverse edge, said latch levers being movable to shift said third roller to a position spaced from one of said pair of rollers a distance greater than the diameter of said platen; and means on each said front post for engaging said transverse edge of the corresponding latch lever, said means being adjustable to maintain said third roller in engagement with said platen. 